1. Field of the Invention
The present invention relates to a soller slit for collimating diverging X-rays to parallel X-rays. Also, the present invention relates to an X-ray apparatus constructed with the same soller slit.
2. Description of the Related Art
There has been known an X-ray apparatus that is an apparatus for analyzing a specimen with using X-rays. Further, there has been known an X-ray apparatus having a structure in which a soller slit for collimating X-rays incident to a specimen or X-rays diffracted by the specimen to parallel X-ray beams by limiting divergence of the X-rays. FIG. 12 shows an example of a conventional X-ray apparatus using such soller slit.
In the X-ray apparatus, a specimen `S` performs the so-called .theta. rotation in which the specimen `s` continuously or intermittently rotates about an axis line Xs of the specimen `s` at a predetermined angular speed, and simultaneously, an X-ray counter 51 performs the so-called 2.theta. rotation in which the X-ray counter 51 rotates about the axis line Xs in the same direction at an angular speed twice the predetermined angular speed. X-rays emitted from an X-ray focal point `F` are directed through a monochromator slit 52, monochromator 53, a soller slit 54 and a divergence limiting slit 56 to the specimen `S`, while the .theta. rotation and the 2.theta. rotation being performed.
The conventional soller slit 54 is constructed by piling up a plurality of thin metal foils 61 with using a spacer between adjacent metal foils, as shown in FIG. 13. A front and rear portions of this soller slit 54 in a propagating direction of an X-ray `R` are opened to allow the X-ray to pass through and side portions thereof are closed by spacers 59 and side walls 62.
In FIG. 12, the soller slit 54 limits divergence of X-rays generated from the X-ray focal point `F` and then reflected or diffracted by the monochromator 53, to form parallel X-ray beams incident on the specimen. In some case, the soller slit is arranged between a divergence limiting slit 57 and a light receiving slit 58 to direct X-rays to an X-ray counter 51 by limiting divergence of X-rays diffracted by the specimen `S`.
In FIG. 12, when Bragg's diffraction condition is satisfied between X-ray incident on the specimen `S` under the .theta. rotation and crystal lattice face of the same specimen `S`, X-ray diffraction occurs at the specimen `S`. Thus diffracted X-rays are detected by the X-ray counter 51 through the scattering ray limiting slit 57 and the light receiving slit 58, which perform 2.theta. rotations, respectively. On the basis of this detection, both the diffraction angle 2.theta. and the X-ray intensity regarding X-rays diffracted at the specimen `S` are measured.
In the X-ray apparatus mentioned above, the soller slit 54 is located in a position remote from other X-ray optical elements such as the monochromator 53 and the specimen `S` as shown in FIG. 12. Therefore, a space dedicated to the soller slit 54 is required, causing the size of the X-ray apparatus to be large.